Increasingly manufacturers are turning to polymers to create surfaces that are resistant to chemical and environmental damage. For example, fluorinated polymers exhibit resistance to damage caused by exposure to chemicals, such as methylethylketone (MEK), resistance to stains, and resistance to damage caused by exposure to environmental conditions. Such polymers have been used in applications, such as airplane and train cargo hold liners, vinyl siding surface treatments, and photovoltaic protective coverings.
For outdoor applications, manufacturers seek to provide weatherable films and, in particular, films that protect underlying surfaces from ultraviolet radiation damage. In addition, the films themselves are desirably resistant to damage caused by ultraviolet radiation. Polymer films using acrylic polymers are especially susceptible to damage caused by ultraviolet radiation. Particular acrylic polymers may leach from the film, undergo free radical damage, or cross-link when exposed to ultraviolet radiation, leading to a change in the physical properties of the polymer film.
As a result, manufacturers add an ultraviolet radiation (UV) absorber to a layer of the polymer film. However, high concentrations of ultraviolet radiation absorber typically result in decreased mechanical performance of the polymer film and haze within the polymer film. In addition, previous authors have noted a leaching of UV absorber from the polymer film leading to decreased performance over time. As a result, the lifetime of the polymer film may be limited and underlying substrates or components may be damaged as the protective film degrades. As such, an improved weatherable polymer film would be desirable.